It's amazing...you explain these topics in 3 or 4 minutes so clearly and precisely compared to college instructors that take 20+ minutes to explain with students still scratching their heads...thank you!
@Kendra51391 You are very much welcome Kendra. It's sometimes hard to understand what the textbook says, so I'm definitely glad that these videos are helping you understand. The nervous system is quite complex, so I'm trying to break it down into bite-sized chunks :)
His way of teaching can turn any layman into a complete genius. I couldn't understand this subject after two hour of reading two giant books. But after watching his video everything became clear. Thanks for the enlightenment.
You have taken the complicated activities of the body and broken them down to plain simple processes. Without a doubt the most informative teaching/instruction I have ever received!
@mage1413 Good question. The Na/K Pump helps mostly with redistributing the ions to their starting position. It's a combination of factors that restores the membrane potential action potential - The Na/K pump, in combination with passive ion channels.
Wow I was staring at a lecture slide for 15 minutes trying to get my head around this chart im looking at with depolar, repolar etc. Shoulda saved my 15 minutes and come straight to you now it makes sense!! Cheers mate.
@efil4aggin92 Well, definitely! Leslie will be there still sharing his knowledge and expertise with everyone as long as he can... have fun and stay tuned for more!
If my cell is at -90 and I want it to get back to -70, then shouldn't the pump bring 3 Na ions IN and 2 K ions OUT? This way we have more positive ions entering than leaving, which means the cell will gradually get more positive and get back to -70. In the video you said the opposite(3 Na ions OUT and 2 K ions IN). How can the cell get more positive if it's losing more positive ions than gaining? That's like if I had a debt of -$90 and wanted to get back up to -$70. How can I possibly get back up to -$70 if i'm constantly losing 3 $10 bills while gaining only 2 $10 bills?
@BDdiva1 You're very much welcome! We're glad to know the videos have been able to help. Do stay tuned because we have more Biology videos coming very soon!
@hmelton1247 You're very much welcome! We are glad to know that you found value on this video and was able to help out. Do come back for more because there are a lot more videos coming very soon! :)
You are exactly the guy that I was expecting to make a website and channel in youtube named "Make Biology Fun". You are perfect. Congratulations. I hope all my teacher be like you.!!!!!!!!!
I love your patience and how you relate to the slow process of AP and BIology student brains, in the words of oliver twist, may i have some more sir, please.
What amazing videos! I've watched all of the action potential videos after trying to understand this concept by listeing to my class lectures, reading my notes and text book and looking at the diagrams. I find your videos and ten minutes later I've got it! I'm in a 200 level college bio class! I'll be telling my class mates about this video for sure!
@AznViperXT Thank you! We'll let Leslie know how much you appreciate his way of sharing knowledge with everyone :) Stay tuned for more because there'll be a lot more Biology videos coming very soon... Enjoy!
after watching i felt like killing myself for wasting my whole day and night trying to understand from the books this action potential and neurons. Mashallah God bless you dear. Thank you so much for helping :D
can you answer this question please choose: the hyperpolarization phase of the action potential is due to : A.the opening of voltage-gated MA channels. B.the prolonged of opening of voltage-gated K channels. C.the closure of resting MA channels . D.due to the closure of Cl channels.
WOW! Life seems a lot easier. I had so mush trouble understanding all these re/de/ hypo /polarization. Now I am sure wake me up in the middle of the night I will be more than happy to tell you all about them:)) THANK YOU SO MUCH!!!
Mr. Samuel, these videos are fantastic content and as a nursing student in my junior year of nursing school, I say bravo and good job of breaking down hugely complicated concepts into bite-sized pieces. Also, your examples are perfect and well considered. I learn more in 10 minutes of watching you than in 2 hours of classroom lecture from MD's. If I could make one professional observation, in my day job I produce a lot of green-screened promo vids for different companies' promotions. As you can see the reflection of the green screen on your desk here, it appears you may be too close to your green screen. It's always better to have a larger green screen and to be as far to the front of it as possible. Also, you see how the green screen sort of melds into your skin tone at places? That is usually caused by uneven lighting, or competing light sources. Green-screening is always best done in a room with zero natural lighting, and only one light source (i.e., every light you use should have an identical color temperature.) Also, I'd play with different screens to see if perhaps blue would work better for you. Best of luck and keep the vids coming!
Thank you! Thank you! Thank you! Thank you! You cleared everything up! I didn't even have questions lingering in my mind after this video! Great teaching skills!
This video really helped! I dont understand something though. If there is 3 Na being pumped out, while 2 K being pumped it, doesn't that make the inside of the cell more negative, since more + ions are leaving than entering it.
I dont get it, if the pump pums 3na+ out and 2k+ in thos will make the inner part of the membrane even more negative than -90mv. How can that lead to -70mv? Please answer im having the exam in three days😭
Dream Seeker the same problem .but i think theirs another channel of potassium that act to enter the potassium inside the membrane and use energy . I think the N-K atpase work to maintane the electrochemical gradiant only!!!!!
@FantasyGrl317 And, thank you too for your support! :) You can go to our website for more Biology videos that you might find interesting. We guarantee you, you'll learn and understand concepts easily. Stay tuned for more!
If 3 sodium ions go out and 2 potassium ions go in, wouldn't the end result be negative? So wouldn't this push the line further below the resting state?
Ok ppl, for some1 who dont undestand why pumpking only + ions make resting place. In the nervous cell we dont only have K+ or Na+. There are also some ions orsubstances making - potencial. When we have repolarisation, K+ ions run out. Imagine if you run very very fast and someone suddenly say you "SP OP!". You cant just stop in the second. Same way K+ ions runs out and leave in some Na+ ions with other - ions. That why we have - potencial in the cell in total. After this Na/K pump try to puts out Na and brings in K ions, 3Na out and 2K in...so, potencial should get down not up BUT...we have also some channels which intantly let in Na ions. Look then, we have Na/K pump, normal Na channels (Na gets in) and normal CLOSED K channels. K+ can get in by pump and can't exit cell by regular K+ channels, Na+ gets out by pump but also gets in by regular channels (in a smaller amount than is excreted). In total more + gets in that out and thay why potecial goes up. Jagiellonian University
Thanks so much, definitely helping me and making biology fun! Ps if you wore a green shirt you'd have neurones on it from your banner thing behind you. That would be pretty cool
thank you!!! very helpful video. Is it correct to say then that the sodium pump is always working away in the backgound or just when there is an action potential?
(Cont)...The only way Na can go out the cell is by sodium/potassium pump, which work against conc gradient (active transport). From an area of Low to High. But thing is Na is lower outside, So Na is going to go from the outside to the inside (as inside is higher conc of Na) and active transports ions from low to high..so Na doesnt end up being high outside, but high outside....I hope this makes sense..Please help
Excuse me, so how about the function of hyperpolarization-activated cyclic nucleotide-gated? HCN and pump Na/K-ATPase work together at hyperpolarization to get the membrane potential to baseline of resting potential?
I love your videos. I send my students to them on a weekly basis. Can you tell me what type of recording equipment you use to make the videos? Especially the audio....
I've used a bunch of different setups so I'm not 100% sure what I used in this video. Now for video I use a Canon 60D For audio, I use a Sennheiser lavalier mic. For my screen recordings, I use Keynote and Screenflow on the mac for recording and I have a number of mics that I've used. Right now I use a Heil PR40 mic in my studio. It's quite an elaborate setup. I went a bit overboard ;)
When the action potential reaches its minimal value (hyperpolarization), the neural membrane is most permeable to which ion(s)? Anions, Ca, Cl, Na or K? Thank you for your help :)
Your videos are incredibly helpful! Thank you. I do have a question though. Can the Potassium ions move before the Sodium ions or do the Sodium ions always move first? My notes seem to suggest that the potassium is switching first, as it shows a trough in the millivolts graph before the peak as Sodium rushes in, rather than after it. Many thanks
HI Can you please help me..im confused During an action potential the inside is more positive: because of high conc of Na and K ions, during repolarisation, K go outside the cell due to concentration gradient and electrical gradient. Inside the cell there is still a lot of Na, this needs to be reversed, so resting potential can be created...
I am soo happy towards this video.i mean this previous video .you even more details about that sir with the help of some set up things.but this vdeo kinda make me not very understands the real situation .i am soryy but if you have some times.can u get me the new videos and the example of this hyperpolarization?tqvm.
Ok guy’s I just need an explanation. When it goes to hyberpolrization and Na3 go out , 2 k go in that mean increase of polarise . How it can get back to RMP
Anyone not get it? If my cell is at -90 and I want it to get back to -70, then shouldn't the pump bring 3 Na ions IN and 2 K ions OUT? This way we have more positive ions entering than leaving, which means the cell will gradually get more positive and get back to -70. In the video he says the opposite(3 Na ions OUT and 2 K ions IN). How can the cell get more positive if it's losing more positive ions than gaining? That's like if I had a debt of -$90 and wanted to get back up to -$70. How can I possibly get back up to -$70 if i'm constantly losing 3 $10 bills while gaining only 2 $10 bills?
Delano, you raise a great question. It seems that in an attempt to simplify things (10 years ago), I ended up oversimplifying things in a way that doesn't fully explain what's happening. When the membrane potential is hyper polarizes, the voltage gated ion channels close. However, there are still passive ion channels and the sodium potassium pump and those are normally doing their jobs. The combination of these (and other factors) result in the membrane potential getting back to the resting potential. It's not just the Na/K pump at work. There are other factors at play. The Na/K pump helps for redistributing the ions back to their original state where Na+ is more concentrated on the outside and K+ is more concentrated on the inside.
@@InteractiveBiology Thank you. Can you tell me what the passive ion channels are or the other channels? What exactly is making the cell more positive? The Na/K pump is really just returning the external/internal concentrations back to normal, but it isn't making the cell more positive.
There are passive Na+ and K+ channels, but many more of the K+ channels than Na+. Remember that the Equilibrium potential for Na+ is somewhere around 60 mV, so it will want to move into the cell to make it more positive. That will play a role in making the membrane potential more positive. But with that, the overall membrane potential will be closer to the equilibrium potential for K+ because of the fact that K+ can more readily cross the membrane due to the higher number of those channels.
@@InteractiveBiology so are you saying the cell will eventually go from -90 to -70(resting state) due to more Na+ entering the cell through passive channels and leak channels?
That is a major factor yes. Na+ enters through those passive ion channels and it wants to move into the cell (even though the Na/K pump is working against it). It's difficult to look at any of the factors in isolation and say that it's the thing that's responsible for the state of the neuron. If there's no action potential taking place (or if it's done), all of the factors will combine to reach resting membrane potential.
I think it's because sodium and potassium ions are, so to speak, the "main components" of the action potential is because the action potential is widely affected by the Sodium and Potassium ions. While chloride ions also play a role in the action potential, the effect is so little that it's just neglected since it does contribute much to the action potential, whereas sodium and potassium are a necessity for the action potential to occur.
